Question: Which Class II combustible liquid has the highest median lethal concentration?
Paraphrase: What Class II flammable liquid has the greatest median dangerous concentration?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q21009057 . ?ent wdt:P2712 ?obj } ORDER BY DESC(?obj)LIMIT 5 
Answer: allyl glycidyl ether, allyl glycidyl ether